Metallic Rattle 3k-3.2k RPM, cold only

[AnotherS197GT]

So I've noticed over the last few weeks, maybe a month, my car has developed an odd metallic rattle right at ~3000-~3200 RPM. Goes away right past that. Doesn't do it in first gear, 2nd and 3rd only. 99% of the time it only happens when the car is cold, but also has happened a few times once at operating temp. It sounds like its coming from the engine.

I don't think its exhaust. I haven't touched my exhaust since November. I did crawl under the car and made sure all the connections are tight last weekend though. Heat shields are all clear of the exhaust, nothing even remotely close to the exhaust to cause this rattle.

Don't think its the separator plate since I have the updated plate.

The only thing I have done to the car in the last month was put on a CAI, engine cover, and re tune. I'm kinda thinking it might be detonation, because it sounds like the descriptions of detonation that I've heard before. Is there anyway to datalog and see if I'm detonating? I'm also thinking it could possibly be phasers, but I really don't want to go there right now.

 

[fdjizm]

Soft sound of marbles in a can?

 

[AnotherS197GT]

Yeah, I guess it kinda sounds like that. If I really had to describe it, I'd say it sounds more like a can of screws.


I sure hope Seer didn't move to Michigan...

 

[fdjizm]

If nothing else is wrong it sounds like a little detonation.
Bad gas? Some jagoff once put 87 in my car when I asked for 93 and I heard the marbles.

 

[AnotherS197GT]

I've tried a few different gas stations. I've been through 6 or more tanks of gas since this issue popped up.

 

[fdjizm]

I'd talk to the tuner and tell them, they may be able to pull a little timing in that range or add fuel.
I don't think that little bit is going to damage much, especially on an NA engine.

 

[Sky Render]

Sounds like mild detonation or "spark knock" to me, too. Can you datalog it?

 

[AnotherS197GT]

I'd like to. I don't know what parameters to log or how to read the graphs though. I did some searching the other day and it looks like you are supposed to monitor KSPARK or something like that, but its not always accurate and there are other parameters to watch. I'd love for a tuning guru to step in here and let me know.

 

[Dubstep Shep]

I would think the engine would pull timing if it was seeing detonation.

Of course that assumes there's timing to pull, and that the knock sensor system is working correctly.

You could always mix some 93 with 110 and see if it goes away. If not, I would begin to doubt it's detonation.

 

[fdjizm]

I use these all the time, should work for our 05-09's.
All you need is a laptop, your tuner and SCT livewire.

ACT CAM ANGLE
AIR CHARGE TEMP
AIR FLOW #/MIN
COOLANT TEMP
fp duty cycle
FUEL SOURCE
LOAD
lt fuel trim b1
lt fuel trim b2
MAF AD COUNTS
PRES DROP F INJ
RPM
short term b1
short term b2
SPARK ADVANCE
SPARK SOURCE
SPK ADD KS
vehicle speed


SPARK ADVANCE, SPARK SOURCE and SPK ADD KS are the ones you're looking for.
You can post a log up for us to look at.

 

[AnotherS197GT]

Thanks Frankie. I'll have to make myself a config file when I get home. I probably won't be able to log until tonight or tomorrow since the car will be warm when I get home.

I would think the engine would pull timing if it was seeing detonation.

Of course that assumes there's timing to pull, and that the knock sensor system is working correctly.

You could always mix some 93 with 110 and see if it goes away. If not, I would begin to doubt it's detonation.

Yes, I think its pulling and thats why it goes away in 100-200 RPM. Thats also what led me to think it was detonation.

As far as 110, there is only 1 place around here that I'm aware of that carries it. Not sure if its leaded or not and I have cats still. I may dump some 93 in it and see what happens though.

 

[Dubstep Shep]

Thanks Frankie. I'll have to make myself a config file when I get home. I probably won't be able to log until tonight or tomorrow since the car will be warm when I get home.









Yes, I think its pulling and thats why it goes away in 100-200 RPM. Thats also what led me to think it was detonation.



As far as 110, there is only 1 place around here that I'm aware of that carries it. Not sure if its leaded or not and I have cats still. I may dump some 93 in it and see what happens though.

Yeaaaa, leaded is no bueno...

 

[Exley]

Sounds to me like the separation plate between the transmission and the engine. Mine does the same thing.

 

[AnotherS197GT]

Sounds to me like the separation plate between the transmission and the engine. Mine does the same thing.

Negative. Had that issue many years ago. Its been fixed. It doesn't sound the same as the plate, and doesn't behave the same as the plate.

 

[s8v4o]

I didn't see you mention when it happens. What I mean is this just at light acceleration, WOT, etc?

How many tanks of gas have you run through it while acting this way?

 

[AnotherS197GT]

I'd say light/medium acceleration. If it happens under WOT I'm in and out of the range where it happens so fast I can't hear it. Plus I don't usually go WOT first thing in the AM.

Its been several tanks of gas. I'd have to say 6+

 

[s8v4o]

Gotcha, thought it might be some bad gas or something. When it's cold it adds more timing. Do you have a wideband? Defiantly do some datalogging and report back.

 

[AnotherS197GT]

I thought so too at first. And I'm thinking the same thing. By the time it's hot, the ECU is pulling enough timing to get ride of the detonation. I'll do some data logging tonight once the car cools down and post up the logs. Go get some higher octane gas and do the same in the AM.

No wideband.

 

[AnotherS197GT]

Alright, got some logs. Unfortunately, I think I also took 14 years off my life trying to get livelink and the sct to work right. And I'm also a fucking idiot and forgot to log RPM.

https://dl.dropboxusercontent.com/u/71054279/first log.csv
https://dl.dropboxusercontent.com/u/71054279/second log.csv

 

[fdjizm]

no RPM, no spark source and no spk add KS pid.
Where did you get all those from? Log what I posted above, much easier to read lol.